MUMBAI (Reuters) - India’s Reliance Industries Ltd (RELI.NS) will launch its ambitious 4G telecoms venture in December through a direct physical presence in over 1,000 “Jio Centers” and will also sell self-branded devices under its retail unit, the company disclosed in a post earnings presentation on Saturday.

The energy conglomerate run by the country’s richest man, Mukesh Ambani, re-entered the telecoms sector in 2010 and has already invested over $15 billion in building the country’s largest 4G broadband network, with commercial operations expected to start in December.

The company will start “extensive” beta tests across the country in the next few weeks to test its network, joint chief financial officer V. Srikanth told reporters on Friday, after the company posted estimate-topping first quarter profit boosted by its highest gross refining margin in six years.

Reliance will use a two-pronged strategy for ensuring device availability, using open market as well as self-branded devices under its retail unit’s electronics arm, Reliance Digital.

“Reliance Digital would be a catalyst by making available entry level to ultra premium 4G LTE smartphones... in driving the device ecosystem in India for Jio,” the company said.

The much-delayed launch and investment in the venture has drawn criticism, but Ambani allayed some concerns when he told shareholders in June that the Jio network will roll out with coverage to about 80 percent of the country’s population.

Apart from the 1,000 ‘Jio Centers,’ the company will have 500,000 connectivity outlets and 1 million additional recharge outlets at launch, the company’s presentation said.

It has also engaged with global smartphone brands including Apple (AAPL.O), Samsung (005930.KS), Huawei [HWT.UL] and Xiaomi [XTC.UL] to ensure availability of 4G devices and pocket routers across price ranges, the company said.

Reuters had reported in May that the company was in talks with Chinese manufacturers to secure cut-price devices that could be bundled with its network and sold in packages at prices as low as $30.